When old gold is melted, a small amount of its weight is typically lost. This isn’t because the gold itself disappears, but rather because of impurities and non-gold alloys that burn off or separate during the melting process.

Impurities and Alloys: Jewelry is not 100% pure gold. It’s mixed with metals like copper or silver to increase durability and strength. During melting, these lighter metals and any surface dirt or dust can vaporize or oxidize.

Soldering: Solder used to join parts of a piece often has a different melting point and composition, which can also contribute to weight loss.

Non-Gold Parts: Stones, clasps, or other non-gold components are removed before melting, and their weight is not included in the final gold weight.

The percentage of weight loss, often called “melt loss,” varies but is usually minimal, often ranging from 0.5% to 2% for well-maintained jewelry.